1. Field of the Invention
The present invention pertains to suturing of bodily or anatomical tissue and, more particularly, to an apparatus and method for suturing anatomical tissue during endoscopic and open surgical procedures.
2. Discussion of the Related Art
Suturing of bodily tissue, that is, the practice of using lengths of suture material to ligate or approximate tissue, is a time consuming part of most surgical procedures including both open surgery and endoscopic or closed surgery. "Open surgery" refers to surgery wherein the surgeon gains access to the surgical site by a relatively large incision and "endoscopic surgery" refers to minimally invasive surgery wherein the surgeon gains access to the surgical site via one or more portals through which endoscopes are introduced to view the surgical site and through which instruments, such as forceps, cutters, needle holders and the like, are introduced to the surgical site.
In the past, suturing has been accomplished with the use of a sharp suture needle carrying a length of suture material, the suture needle being caused to penetrate and pass through the tissue pulling the suture material through the tissue. Once the suture material has been pulled through the tissue, the surgeon ties a knot in the suture material. The knotting procedure allows the surgeon to adjust the tension on the suture material to accommodate the particular tissue being sutured and to control approximation, occlusion, attachment or other conditions of the tissue.
The process of tissue penetration and knotting of the suture material can be time consuming and tedious work, particularly when performed in connection with microsurgery and endoscopic surgery and can unduly prolong the duration of surgery and therefore the period in which the patient is under anesthesia. Nevertheless, endoscopic surgery is preferred over open surgery due to the greatly reduced trauma and wound healing time for the patient and due to cost savings associated with shorter hospital stays and performing surgery in non-hospital or out-patient surgery sites. Accordingly, there has been much effort to develop techniques for facilitating the suturing normally performed by use of a suture needle and a length of suture material. Alternative techniques proposed have included electrical coagulation, mechanical devices such as clips, clamps and staples, and lasers. However, no alternative technique has yet been well accepted by surgeons to produce the results obtained by suturing and knotting. Thus, there is a great need for suturing techniques useful in endoscopic surgery to permit surgeons to suture anatomical tissue using suture needles and lengths of suture material in a time efficient, consistent and precise manner.
The performance of an endoscopic procedure typically involves creation of one or more puncture sites through a wall of an anatomical cavity using a penetrating instrument including an obturator, such as a trocar, disposed within a portal sleeve. After the penetrating instrument has penetrated into the anatomical cavity, the obturator is withdrawn leaving the sleeve in place to form a portal in the cavity wall for the introduction of instruments such as endoscopes, scissors, forceps, needle holders and the like (known generally as "end effectors") into the anatomical cavity.
Suturing is typically performed with a needle holding instrument, or needle holder, having a pair of jaws adapted to hold the body of a suture needle. The jaws of the needle holding instrument are inserted through the portal sleeve and are positioned at the operative site by manipulation of a handle at the proximal end of the instrument outside the body. With a suture needle held between the jaws of the needle holding instrument, the handle is manipulated to cause a tip of the needle to be pushed through the tissue being sutured. Once the tip of the suture needle has been pushed through the tissue, the jaws of the needle holding instrument are opened to release the suture needle so that the tip of the needle can be grasped and pulled through the tissue therewith, or, after opening the jaws, a second needle holding instrument is introduced at the operative site through another portal to grasp the tip of the suture needle after it has emerged from the tissue being sutured. These techniques require difficult manipulation of the needle holder of the suture needle within the jaws of the needle holder before another stitch can be made.
Of course, it is also generally desirable to minimize the size of each puncture site. Further, in order to permit a wide range of tissue sizes to be sutured, it is desirable to provide a needle holder that moves through a path having a large radius of curvature, i.e. a large working span. These objectives, small size of punctures, and a large working span, are seemingly contradictory. Conventional devices have not achieved the above-noted objectives in a satisfactory manner.